2 dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_CEILL],
9 m4_divert_text([DEFAULTS], [gl_ceill_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 dnl Persuade glibc <math.h> to declare ceill().
12 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
13 dnl Test whether ceill() is declared.
14 AC_CHECK_DECLS([ceill], , , [[#include <math.h>]])
15 if test "$ac_cv_have_decl_ceill" = yes; then
16 dnl Test whether ceill() can be used without libm.
18 if test "$CEILL_LIBM" = "?"; then
19 dnl Sun C 5.0 on Solaris declares ceill() and has it in the system-wide
20 dnl libm.so, but not in the libm.so that the compiler uses.
23 m4_ifdef([gl_FUNC_CEILL_IEEE], [
24 if test $gl_ceill_required = ieee && test $REPLACE_CEILL = 0; then
25 AC_CACHE_CHECK([whether ceill works according to ISO C 99 with IEC 60559],
26 [gl_cv_func_ceill_ieee],
29 LIBS="$LIBS $CEILL_LIBM"
32 #ifndef __NO_MATH_INLINES
33 # define __NO_MATH_INLINES 1 /* for glibc */
36 ]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
37 ]gl_LONG_DOUBLE_SIGNBIT_CODE[
38 static long double dummy (long double f) { return 0; }
39 int main (int argc, char *argv[])
41 long double (*my_ceill) (long double) = argc ? ceill : dummy;
42 /* Test whether ceill (-0.3L) is -0.0L. */
43 if (signbitl (minus_zerol) && !signbitl (my_ceill (-0.3L)))
48 [gl_cv_func_ceill_ieee=yes],
49 [gl_cv_func_ceill_ieee=no],
50 [gl_cv_func_ceill_ieee="guessing no"])
53 case "$gl_cv_func_ceill_ieee" in
62 if test $HAVE_DECL_CEILL = 0 || test $REPLACE_CEILL = 1; then
63 dnl No libraries are needed to link lib/ceill.c.
66 AC_SUBST([CEILL_LIBM])
69 # Determines the libraries needed to get the ceill() function.
71 AC_DEFUN([gl_FUNC_CEILL_LIBS],
73 gl_CACHE_VAL_SILENT([gl_cv_func_ceill_libm], [
74 gl_cv_func_ceill_libm=?
77 [[#ifndef __NO_MATH_INLINES
78 # define __NO_MATH_INLINES 1 /* for glibc */
83 [gl_cv_func_ceill_libm=])
84 if test "$gl_cv_func_ceill_libm" = "?"; then
89 [[#ifndef __NO_MATH_INLINES
90 # define __NO_MATH_INLINES 1 /* for glibc */
95 [gl_cv_func_ceill_libm="-lm"])
99 CEILL_LIBM="$gl_cv_func_ceill_libm"